Get a phrase with a missing word in Russian translation.

GET /api/word-pairs/phrase_completion/?format=api
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "word_pair": {
        "id": 354,
        "french_word": "j'ai soif",
        "russian_word": "я хочу пить",
        "category": "phrase",
        "category_display": "Phrase",
        "level": 5,
        "level_display": "Small Phrases",
        "comment": "I'm thirsty",
        "tags": [],
        "created_at": "2026-01-17T18:41:48.159471Z",
        "updated_at": "2026-01-17T18:41:48.159481Z",
        "is_active": true
    },
    "french_phrase": "j'ai soif",
    "russian_phrase": "я хочу пить",
    "partial_russian_phrase": "я хочу _____",
    "missing_word": "пить",
    "missing_word_index": 2,
    "options": [
        "любить",
        "пить",
        "ходить",
        "звать",
        "идти"
    ],
    "correct_index": 1
}